CICD

add `help` (and `?`) commands to numbat REPL #377

Job	Run time
Ensure 'cargo fmt' has been run	11s
Documentation checks	6m 54s
Extract crate metadata	4s
Minimum supported rust version	2m 45s
aarch64-unknown-linux-gnu (ubuntu-20.04)	3m 57s
arm-unknown-linux-gnueabihf (ubuntu-20.04)	5m 32s
arm-unknown-linux-musleabihf (ubuntu-20.04)	2m 42s
i686-pc-windows-msvc (windows-2019)	8m 26s
i686-unknown-linux-gnu (ubuntu-20.04)	3m 47s
i686-unknown-linux-musl (ubuntu-20.04)	2m 19s
x86_64-apple-darwin (macos-12)	3m 24s
x86_64-pc-windows-msvc (windows-2019)	7m 34s
x86_64-unknown-linux-gnu (ubuntu-20.04)	2m 13s
x86_64-unknown-linux-musl (ubuntu-20.04)	3m 38s
	53m 26s

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